Impact of soft handover and pilot pollution on video telephony in a commercial network

Soft handover (SHO) provides better support for user mobility. The quality of service (QoS) to the mobile wireless subscribers can also grant benefits from SHO. To analyze the impact of SHO on the circuit switched (CS) video telephony (VT); real-time measurements have been conducted on a commercial WCDMA mobile network in the CBD of Sydney, Australia. Live measurement provides a practical approach to evaluate performance of commercial network. The obtained SHO gain implies that better QoS can be achieved. Furthermore, the negative impact of pilot pollution on radio link quality has been demonstrated in this paper. ©2010 IEEE

Specifying and Verifying Requirements for Transmission of Medical Data in Public Networks

The purpose of this study is to identify and verify the necessary Quality of Service metrics in public networks for an existing remote patient monitoring system called Mobile Viewers. Therefore, any abnormalities can be detected beforehand and the application quality can be seen from the end user's point of view. The name Mobile Viewers refer to three different client applications: Web Viewers, Pocket Viewers and Cellular Viewers. The literature part of this thesis reviews the former research studies dedicated to network performance measurements in 3G, 2.5G and Wireless LAN networks. Based on the review, the most suitable measurement methods, tools, metrics and environments are selected to be utilised during this study. In the first part of the thesis work, passive live measurement tests are executed within UMTS, GPRS, LAN and Wireless LAN networks in order to find out the delay, jitter and packet loss metrics for the individual Mobile Viewers. As a result, GPRS presents the highest delay, jitter and packet loss values leading to poor application quality. The second part of the thesis study focuses on identifying the quality requirements for Mobile Viewers. Initially, a network emulator tool is employed to emulate the necessary delay, jitter and packet loss metrics in order to test the application quality under different network conditions. Additional subjective user defined tests are executed to assess the quality for each viewer client. Finally, the limit delay, packet loss and jitter values, where the application quality starts to degrade, are presented. Additional future work may be carried out by observing the Mobile Viewers' performances with higher technologies for instance, HSDPA. Furthermore, the conclusions derived from the analysis of the measurements and the proposed requirements for Mobile Viewers should be validated by additional experiments with different client devices, measurement tools and longer measurement periods